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DIFFERENTIAL SPEED AND REVERSING GEAR FOR MOTOR CARS,

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No. 593,652. Pen tented Nov. 16,1897.

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No. 593,652. Patented NOV." 16, 1897,-

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UNITED STATES ATENT' FFICE.

GEORGE G. M. HARDINGHAM, OF LONDON, ENGLAND.

DIFFERENTIAL SPEED AND REVERSING GEAR FOR MOTOR-CARS, TRAM-CARS, &c.

SPECIFICATION forming part of Letters Patent No. 593,652, dated November16, v1 897. Application filed May 24,1897. Serial No. 637,934. (Nomodel.) Patented in England December 8, 1896, No. 28,100.

To all whom it may concern.-

Be it known that I, GEORGE GATroN MEL- I-IUISH HARDlNGHAM, a subject ofthe Queen of Great Britain and Ireland, residing at 191 Fleet Street, inthe city and county of London,

England, have invented certain new and useful Improvements inDifferential Speed and Reversing Gears for Motor-Oars, Tram-Oars,Velocipedes, and other Road-Carriages, (in respect whereof I haveapplied for Letters Patent in Great Britain to bear date December 8,1896,-No. 28,100,) of which the following is a specification.

This invention relates to differential speedgears of the kind in whichepicyclic' gear trains are employed; and it consists, first, in animproved mode of construction whereby two different speeds in onedirection and one speed in the opposite direction are afforded, and,secondly, in improved means for eife'cting a large variation in speedbetween the motor or other driving-shaft and the changegear.

Differential speed-gear constructed according to my improved method andadapted for enabling a motor-car or other road-carriage to be driven attwo different speeds in one direction, and also to be driven in thereverse direction, is illustrated in the accompanying drawings, where0f'Figure 1 is a longitudinal section. Figs. 2 and 3 are sectionalelevations on the lines 3 s The apparatus comprises three trains of.

spur-gear, one for the high speed, another for the low speed, and athird for the reverse speed. Each consists of a central pinion, a

surrounding internally-toothed wheel, and an intermediate wheel, or apair or set of intermediate wheels,carried on an axially-mounted bodyand gearing with the central pinion and with the outer wheel. One of theelements of each gear-train is, moreover, capable of beingheldstationary or of being released, ac-

Fig. 4 is a side ele-' cording to whether such gear-train is required tobe operative or inoperative.

Referring to the construction illustrated by Figs. 1 to 5, the manner inwhich the several elements of the respective gear-trains are connectedwith the source of power and with the shaft or other part to whichmotion is to be imparted is of the following character:

In the low-speed gear the central pinion A is connected with thespur-wheel H or source of motive power, the body B, carrying theintermediate wheel or wheels I) b, is secured to the shaft D by means ofthe auxiliary carrier B (hereinafter further referred to,) and the outerwheel 0 is held stationary by a friction-strap E or other releasabledevice. In the high-speed gear the central pinion A is held stationaryby a friction-strap E or shaft D, (wheel-hub or other part to whichmotion is to be imparted,) and the outer wheel 0 is held stationary by afriction-strap E or other releasable device. In this last-mentioned casethe intermediate wheels b b are supported on opposite sides by thecarriers 13 B which are bolted together, as shown in Fig. 1. The wheelsb 'b are arranged in pairs, as shown in Fig. 3, one of these, 12 beingmounted at a greater distance from the center than the other. While theformer, b meshes with the outer wheel 0 the latter, b meshes with thecentral pinion A and the two wheels 12 b mesh together.

Where a high-speed engine is employed, it is preferable to reduce thespeed of rotation before applying the power to the change-gear,

are carried on studs mounted in the disk B which latter carries atoothed ring or spurpinion II for engaging with the spur-wheel II. Thesurrounding toothed wheel 0 may be permanently fixed or may betemporarily held by means of a friction-strap E, as before described. Inthe latter case, upon the strap being slaekened and the drum F released,the transmission of power from the motor to the change-gear is entirelyinterrupted.

lVhen it is desired to apply the power of a high-speed engine axiallyinstead of constructing each gear-train to afford a'large reduction, Iprovide the shaft with a sleeve and mount the several gear-trainsthereon, as illustrated in Figs. 6 to 9, the shaft being connected withthe sleeve through reducing-gear of the epieyelic type. The drivingpower is in this instance applied axially and is transmitted fromtheshaft I)" through the central pinion A to the intermediate wheel-carrierB, the outer wheel C being fixed or held by means of the friction-strapE The motion imparted to the intermediate wheel-carrier B iscommunicated to the sleeve D, and thus to all three speed-gears. In thehigh-speed gear the central pinion A is held stationary by means of thefriction-strap E, the intermediate wheel-carrier B is connected with orforms part of the road-wheel II, and the cirenmscribing toothed wheel Cis secured to the sleeve D. In the low-speed gear the central pinion Ais secured to the sleeve D, the intermediate wheel-carrier B isconnected with or forms part of the road-wheel H, and the outer wheel Cis held stationary by means of the friction-strap E. In the gear fordriving in the reverse direction the central pinion A is connected withthe sleeve D, the intermediate wheelcarrier 3 is in connection throughthe intermediate wheel-carrier B with the road-wheel II, and the outerwheel 0 is held stationary by means of the frictionstrap E Either of thetriplex speed-gears hereinbefore described may be modified and convertedinto a duplex speed-gearby omitting the geartrain designed to drive inthe reverse direction.

It will be observed that by employing reducing-gear arranged in eitherof the modes described with reference to Fig. 1 or Fig. 6 the increaseor decrease of speed (as the case may be) accomplished by eachgear-train may be kept within moderate limits, although the speed of themotor or other operating shaft may be relatively high. It will also beperceived that the differential speed-gear described with reference toFig. 6 resembles in all essential particulars that described withreference to Fig. 1, except that in the one case the power is appliedaxially and yielded eireumferentially, while in the other case the poweris received circumferentially and yielded axially.

)Vhat I claim as my invention, and desire to secure by Letters Patent,is

1. The improved duplex driving-gear, comprising two gear-trains, eachconsisting of three elements, namely, a central pinion, an intermediatewheel or set of intermediate wheels carried on an axially-mounted body,and a surrounding internally-toothed wheel, the intermediatewheel-carrier pertaining to each gear being connected with the drivenpart, the central pinion of the one gear and the outer wheel of theother gear being connected with the driving part, and holding devicesfor the outer wheel of the one gear and the central pinion of the othergear, whereby either the one gear or the other gear may be renderedoperative or inoperative, substantially as herein described.

2. The improved triplex (duplex and reverse) driving-gear, comprisingthree geartrains, each consisting of three elements, namely, a centralpinion, an intermediate wheel or set of intermediate wheels carried onan axially-mounted body, and a surrounding internallytoothed wheel, theintermediate wheel-carriers of the first (high) and second (low)speedgears being connected with the driven part, the outer wheel of theone gear and the central pinion of the other gear being connected withthe driving part, and holding devices for the central pinion of the onegear and the outer wheel of the other gear, in combination with a gearhaving its elements connected in the same manner as the low-speed gear,the intermediate wheels of the third gear being duplicated and meshingwith the central pinion and the outer wheel respectively and with oneanother, so as to reverse the direction of rotation, substantially asherein described.

3. The combination, with a change-gear mechanism, of speed-reducing gearcomprising a motor or driving shaft D, a central pinion A connected withthe said shaft, a sleeve D in which the said shaft rotates and whereonthe change-gear trains are mounted, an axially-mounted body B keyed onsaid sleeve, an intermediate wheel or set of intermediate wheels carriedon the said body and a surrounding internally-toothed wheel 0'' capableof being held stationary, the intermediate wheel or wheels meshing withthe central.

pinion and with the surrounding internallytoothed wheel, substantiallyas herein described.

G. G. M. HARDINGIIAM. lVitnesses:

F. J. RAPSON, W. F. CAIN.

